Which of the following is NOT a characteristic of the jump blues?

Why did theorists find it necessary that organum include oblique and contrary motion rather than limiting it to strict parallel motion?

What will be an ideal response?

When did the era of "modern jazz" begin?

a. with swing in the late 1930s b. with bebop in the mid-1940s c. with hard bop in the 1950s d. with free jazz in the 1960s